In the related art, a commodity sales data processing apparatus often performs a sales registration and settlement processing of a commodity by reading commodity information relating to the commodity from an RFID (Radio Frequency IDentifier) tag attached to the commodity. For example, a device may read commodity information from the RFID tag of a commodity when the commodity (alone or contained in a shopping basket) is placed on an upper surface of a checkout counter with an embedded flat antenna.
Recently, an increasing number of stores employ a self-checkout apparatus (i.e., self-checkout point of sales (POS) apparatus) to perform the sales registration and settlement processing of a commodity by a customer.
When performing the sales registration of a commodity with the RFID tag described above, an operator (customer) performing a reading operation places the commodity or the shopping basket within a pre-set transmission range of radio waves. However, some commodities may not be readable depending on an overlapping state of the commodities (RFID tags), an arrangement state, or the like if the shopping basket containing commodities is placed in the transmission range of radio waves. In such a case, the operator looks for a commodity of which reading is not yet completed in the shopping basket. However, since the commodity is mixed with commodities of which reading is completed, work of looking for the commodity is troublesome and there is room for improvement in terms of operability thereof.